This invention relates to apparatus to preserve and rejuvenate items to be stored in a very high humidity atmosphere such as garden vegetables and the like. In particular, the apparatus is preferably utilized in a household refrigerator wherein the items are kept at a cool and above-freezing temperature.
Moisture is lost when vegetables are stored below optimum humidity levels, generally 95% to 98% relative humidity. The process is desorption from the surface of the vegetable, followed by moisture migration from the interior, more surface desorption, etc., until the vegetable is thoroughly desiccated. It has been known for a long time that it is advantageous in order to preserve vegetables to provide some means for hydrating them. Generally, this has been accomplished by providing an atomized spray or fine mist of water that is distributed as a light film on the vegetables. For example, one such arrangement is disclosed in Bird U.S. Pat. No. 2,039,768 wherein a reciprocating nozzle is used to hydrate vegetables. It is also well known that vegetables are preserved by refrigeration and particularly at a high relative humidity. Generally, this kind of atmosphere for the preservation of vegetables is obtained by storing them in vegetable bins located in an above-freezing compartment of a refrigerator. An example of one type of such arrangement is shown in Zearfoss, Jr. U.S. Pat. No. 3,088,290.
In Corrigan U.S. Pat. No. 4,179,900, there is disclosed a system for preserving fresh vegetables in a refrigerator by applying a fine mist made up of particles of about 75-150 micron diameter suspended in air and slowly falling. The mist used in Corrigan is produced by hydraulic pressure means or air pressure.
It is known that water particles may be produced having a smaller diameter than particles formed by hydraulic or pneumatic pressure nozzles and these are formed by an ultrasonic wave nebulizer device. These devices are commonly utilized for nebulizing various liquids and are used as room vaporizers but do not involve heat of vaporization. An example of such a device is disclosed in Mitsui et al U.S. Pat. No. 3,901,443. Environmental control systems such as for preventing frost damage to crops have utilized large size equipment in which water droplets having diameters in the range of from about 5 to 50 microns have been used to cover the crops.
By this invention, there is provided apparatus for preserving and rejuvenating items to be stored in a very high humidity atmosphere, such as garden vegetables and the like, by utilizing a fog of water particles that are so small that they do not settle out to any substantial degree for a very long period of time and surround and engulf the vegetables to provide a very high humidity condition by staying in air suspension many times longer than water droplets produced by hydraulic or pneumatic pressure nozzles.